The biochemical and microbiological quality of palm wine samples produced at different periods during tapping and changes which occured during their storage

This study aimed at establishing biochemical and microbiological properties of different week-old fresh palm saps and assess whether changes occurring during storage of the fermenting saps could affect their quality. Based on the proximate and microbial analysis results, some differences in chemical compositions between fresh palm wine samples were observed. In general, the first day samples were very sugary (50% w/v) with the lowest loads of yeasts (3.2 ± 1 103 cfu/ml), while lactic, citric, tartaric acids and yeast population were characteristics related to both saps collected the second and third weeks of tapping. However, the fourth week wine samples were characterized by high ethanol (3.18 ± 0.06%) and acetic acid (0.767 ± 0.06 g/l) rates. During the storage, accumulation of alcohol occurred in all palm wine samples with the concurrent lactic and acetic acid fermentation taking place as well. Yeasts and lactic acid bacteria population also changed with undoubtedly influence on the palm wine quality.

► The chemical and microbial properties of different week-old palm wines were assessed. ► The first day samples were very sugary, with the lowest yeast loads. ► Lactic, citric, tartaric acids and yeasts were characteristics related to 2nd and 3rd week wines. ► Accumulation of alcohol occurred in all palm wine samples during the storage. ► Yeasts and lactic acid bacteria population changes influence on the palm wine quality.